Spectroscopic properties of heavily Ho^3＋ -doped barium yttrium fluoride crystals

The 30 at.% Ho: BaY2F8 crystals were grown by the Czochralski method, and their spectroscopic properties are analyzed systematically by standard Judd–Ofelt theory. The Judd–Ofelt intensity parameters are estimated to be ?2 =6.74 × 10-20cm2, ?4 = 1.20 × 10-20cm2, and ?6= 0.66 × 10-20cm2, and the fluorescence branching ratios and radiative lifetimes for a series of excited state manifolds are also determined. The emission cross sections with our measured infrared luminescence spectra, especially important for 4.1 μm, are calculated to be about 4.37 × 10-21cm2. The crystal quality is preliminarily tested through a mid-infrared laser emission experiment.